skyline turbo issues

[sparra04]

I am having some issues with the turbo system on the wifeys r33 skyline and need some help re diagnosing the actual problem??

when we bought it 5 mths ago it was breaking down under high rpm/ boost, figured new coilpack would solve it as the originals do fail, it wasn't an issue unless you were wringing its neck so I still haven't replaced coils
in the last week or so it has been stalling when it comes off light throttle/ brake so I checked blow off valve today as they can fail and cause similar issues
well F&%&^ me it was blocked off with a sneaky gasket
not good for the turbo so I have been told
so it looks like bov is working? , replaced with new gasket and refitted
now its loosing boost, gets up to bout 7 psi and suddenly dies in the arse and boost gauge shows loss of boost, take foot off and drive off boost its all running sweet
I have ordered a new bov, but after reading a bit thisarvie I am thinking the waste gate may be creeping causing me to loose boost

any ideas??
cheers

 

[Malicious]

Bov have pros and cons, is it a plumb back or a sneezey one?
It could be opening too easy

 

[BigMik3]

Boost leak maybe around where the pipes join?

 

[Old.Tony]

Is the wastegate sealing properly? How about the wastegate control, is that working?

 

[bods]

If it was boosting OK before you removed the blanking plate I'd say the bov is the problem, probably why they blocked it in the first place..... There's a lot of debate whether turbo flutter (happens on a petrol engine with no bov on rapid throttle closing) is actually bad for turbos or not.... I'd be looking at bov to start with as if it has one fitted from the factory I'd leave it there, which it sounds like you are.

 

[unkn0wn]

If it was boosting OK before you removed the blanking plate I'd say the bov is the problem, probably why they blocked it in the first place..... There's a lot of debate whether turbo flutter (happens on a petrol engine with no bov on rapid throttle closing) is actually bad for turbos or not.... I'd be looking at bov to start with as if it has one fitted from the factory I'd leave it there, which it sounds like you are.

Agreed, they obviously blocked it for a reason.
its not that bad to run the car without a BOV, just get more cool induction noises!
if you do replace it, get something better - like a turbo-smart one etc etc.

I am having some issues with the turbo system on the wifeys r33 skyline and need some help re diagnosing the actual problem??

when we bought it 5 mths ago it was breaking down under high rpm/ boost, figured new coilpack would solve it as the originals do fail, it wasn't an issue unless you were wringing its neck so I still haven't replaced coils
in the last week or so it has been stalling when it comes off light throttle/ brake so I checked blow off valve today as they can fail and cause similar issues
well F&%&^ me it was blocked off with a sneaky gasket
not good for the turbo so I have been told
so it looks like bov is working? , replaced with new gasket and refitted
now its loosing boost, gets up to bout 7 psi and suddenly dies in the arse and boost gauge shows loss of boost, take foot off and drive off boost its all running sweet
I have ordered a new bov, but after reading a bit thisarvie I am thinking the waste gate may be creeping causing me to loose boost

any ideas??
cheers

if you haven't replaced the coils, have you at least looked at the spark plugs?
i prefer to run copper plugs, as most times the fancy ones aren't worth the hype and will cause major issues if you have the wrong heatrange ones.

rul of thumb for these pretty much every turbo nissan - stock gap is 1.1, but if you up the stock boost or have breakdown issues, re-gap to 0.8. your idle may be affected, but you will not blow out the spark and have constant spark on boost.

personally id drop in a set of 'yellowjackets' coil packs. i did this on a mates r34 and couldn't belive the difference, we immediately put the gap up to 1.1 and it has no hesitations (previously would) strong idle and more torque - these are cheaper than spitfires and a great coil, highly recommended.

now they will hesitate if your air reading is wrong, i cant stress this enough to check all the IC pipes are joined corectly, no leaks, no missing vac lines, nothing like that, makeup a pressurised leak tester if you want to be sure, if your losing air pressure, the car does not know how to compinsate for this.

the air levels are read with the afm, make sure this is clean, you can remove it and clean the element with electrical contact cleaner.
if the afm reading certain air levels, and your engine is leaking it out of a pipe/join etc - it will be getting more fuel then it needs and wont run very well.

turbine actuator wont cause it to go from 7psi to nothing.
usually its losing air @ 7psi or something is triggering the ecu to say ****you. do you get any ecu lights? have you tried a ob2 + phone app to follow ecu movements?

boost cut should be around 14psi on this, so 7psi is to low, unless the afm is reading 14psi and the cars getting 7 due to an airleak.

do you have an aftermarket ECU?

i could go on about this ,
might be best to check the above and let me know, then we will move on from there.

 

[sparra04]

thanx for the quick replies
1, wastegate is internall
2, bov is std
3, BKR6E plugs fitted and gapped to 0.8 (2 mths ago)
4, maf was cleaned with crc maf cleaner yesterday
ime guessing they blocked bov to get the flutter noise (car purchased from Sydney) or maybe it was faulty ??
I have heard about yellow jacket coils and was planning to fit a set soon

new turbosmart bov on the way from melbourne
I cant see air leaks anywhere,all looks ok
until I unblocked bov I was pushing 11-12 psi boost before it started to break down
could it be possible the bov is faulty and opening while under boost
I still also am worried there is damage to wastegate???
might be time to rip turbo off and have a look
I will remove manual boost controller thisarvie and see if that helps,could it be faulty and sending wastegate mixed signals ??
where has all my boost gone I want it back
cheers

 

[navaranewb]

ok sparra a bit of information in this thread that isnt exactly correct. These are completely different in turbo design to the NAVs etc. The factory BOV would be blocked as they bleed boost. this will not cause an issue on your side.

Yellow jacket are no good. Avoid as much as you can. If you want i have a set of split fires you can have for the price of the yellow jackets. we can test them if you like

1. Is the car blowing smoke?
2. how are you controlling boost?
3. When it dies does it miss fire or just drops boost?
4. plugs you can try the BCP variants with inbuilt resister (tho i dont think this is your issue)
5. Wastegate wont be an issue. You can test this by hand to see if it moves freely. Its likely going to be stuck open or shut! so will either make barely any boost of over boost to the wazoo
6. As for the new BOV what model did you get? If it vents and not plumbed back it will cause the car to stall.

If you are free on the weekend drop by and we can do some diagnostics.

 

[unkn0wn]

thanx for the quick replies
1, wastegate is internall
2, bov is std
3, BKR6E plugs fitted and gapped to 0.8 (2 mths ago)
4, maf was cleaned with crc maf cleaner yesterday
ime guessing they blocked bov to get the flutter noise (car purchased from Sydney) or maybe it was faulty ??
I have heard about yellow jacket coils and was planning to fit a set soon

new turbosmart bov on the way from melbourne
I cant see air leaks anywhere,all looks ok
until I unblocked bov I was pushing 11-12 psi boost before it started to break down
could it be possible the bov is faulty and opening while under boost
I still also am worried there is damage to wastegate???
might be time to rip turbo off and have a look
I will remove manual boost controller thisarvie and see if that helps,could it be faulty and sending wastegate mixed signals ??
where has all my boost gone I want it back
cheers

if the bov was blocked of previously, then there is no way it was opening.

waste-gate wont make you lose all boost boost.
if your BC is playing up, it would either run to much boost and cause it to hit boost cut, or spike and got back to standard level of boost (7.5psi)
its not like a navara, they cant really lose all boost duie to turbine/electrical fault.

MBC can get dirty/rusty and cloged up.
they are all pretty simple design, take it all apart, and get some wd 40 to lube it all back up, then reconnect it.
as your having issues i would try and aim to set the car to 10 psi first and see how it goes.
13psi is coming pretty close to boost cut on most skylines....

whitch is an option, if your boost is quickly spiking, boost cut will cause the car to jerk around and lower fuel and generally be unhappy.

ok sparra a bit of information in this thread that isnt exactly correct. These are completely different in turbo design to the NAVs etc. The factory BOV would be blocked as they bleed boost. this will not cause an issue on your side.

Yellow jacket are no good. Avoid as much as you can. If you want i have a set of split fires you can have for the price of the yellow jackets. we can test them if you like

1. Is the car blowing smoke?
2. how are you controlling boost?
3. When it dies does it miss fire or just drops boost?
4. plugs you can try the BCP variants with inbuilt resister (tho i dont think this is your issue)
5. Wastegate wont be an issue. You can test this by hand to see if it moves freely. Its likely going to be stuck open or shut! so will either make barely any boost of over boost to the wazoo
6. As for the new BOV what model did you get? If it vents and not plumbed back it will cause the car to stall.

If you are free on the weekend drop by and we can do some diagnostics.

each there own mate, ive got nothing buy praise for yellow-jackets on first hand experience
and once again, having first hand experience with a spitfire coil failing within a year leaves a bad taste in the mouth.

cheers,

 

[navaranewb]

each there own mate, ive got nothing buy praise for yellow-jackets on first hand experience
and once again, having first hand experience with a spitfire coil failing within a year leaves a bad taste in the mouth.

cheers,

11 years experience of building skylines would tell me other wise...

anyway sparra offer is there if you want to test them. Were running on 400wkw with BP98 no issues but again the issue doesnt sound like a spark issue.

 

[Sunny Coaster]

When mine was breaking down under high rpm/boost ( 10psi ) I found that the fuel pump was failing, replaced it with I think a bosch 044 pump and away it went with no probs at all

 

[jjohn]

You reminded me of my rx4 days. Had replaced the electric fuel pump to higher volume one and worked fine for months.
Started breaking down at high sustained revs. Found it had shaken the earth loose,so it was running but intermittently.

 

[sparra04]

thanx again for the input guys

its not blowing smoke , but when you give it a lungfull it does look to be running rich for a second or 3
boost is controlled manually under hood
when it dies it doesn't cough and splutter it just stops firing instantly and boost drops

the bov I have purchased is a std plumb back



I have had my suspicions regarding fuel pump and think I will replace it
my research suggests the std one flows at about 255 lph
so I have purchased this one, looks like a busy weekend


if the above fail to fix it I will have to throw some coil packs at it
the cars original dual stage boost has been unplugged and it runs an aftermarket boost gauge with manual boost adjustment
how does the ecu manage boost and activate boost cutout, where does its info come from?
when wifey gets home from work I will remove manual boost controller and see if that makes any difference
I might fit the go pro under hood and take it for a drive to collect some footage

I am reluctant to take it to a mech or dyno until we get a good start point with new bits fitted

 

[unkn0wn]

how does the ecu manage boost and activate boost cutout, where does its info come from?
when wifey gets home from work I will remove manual boost controller and see if that makes any difference

from another site :
Air flow cut is triggered when AFM voltage exceeding threshold voltage. Air flow cut starts at 4000rpm and threshold increases as a function of rpm up to about 5000 rpm. When it triggers, it cuts fuel and ignition...It is designed to protect against boost control failure...

same thread also suggests above 10-11 psi this will occur, however in my experience its usually 14 or so psi....but i could be wrong, have been wrong before.

it would be a noteable idea to remove the MBC altogether and run standard boost, see how the car reacts.
if the wife is not power hungry, you might even want to leave it there.

to change the ecu limits you would need a third party controler or ecu chip, NISTUNE do an easy enough chip to install and re-map for lightly modified cars..and you can have them send you the map with changed values for boost cutting, or have none at all.

 

[navaranewb]

waste of time disconnecting the boost controller. Would be easier to wind it back to lower the boost. Manual boost controllers just have a vacumm hose and t piece to a little valve between the wastegate and actuator (unless its an electronic version but theory is the same) but wont go lower than the wastegate spring of 7psi

RB25 will have a pressure sensor on the intake side of the engine reading the positive pressure (which is where your gauge will be reading it from) MAF will also send signals depending on what the car is doing. There is plenty that can be done here. Also intake pipe could be closing and is a common problem on there too

 

[navaranewb]

from another site :
Air flow cut is triggered when AFM voltage exceeding threshold voltage. Air flow cut starts at 4000rpm and threshold increases as a function of rpm up to about 5000 rpm. When it triggers, it cuts fuel and ignition...It is designed to protect against boost control failure...

same thread also suggests above 10-11 psi this will occur, however in my experience its usually 14 or so psi....but i could be wrong, have been wrong before.

it would be a noteable idea to remove the MBC altogether and run standard boost, see how the car reacts.
if the wife is not power hungry, you might even want to leave it there.

factory turbos usually fail at around 12psi. If this has a fmic and turbo back zaust then the boost will already be around 13psi at the turbo before the controller is working.

so taking it out if its not required would be a good idea once the diagnosis is found.

 

[sparra04]

waste of time disconnecting the boost controller. Would be easier to wind it back to lower the boost. Manual boost controllers just have a vacumm hose and t piece to a little valve between the wastegate and actuator (unless its an electronic version but theory is the same) but wont go lower than the wastegate spring of 7psi

RB25 will have a pressure sensor on the intake side of the engine reading the positive pressure (which is where your gauge will be reading it from) MAF will also send signals depending on what the car is doing. There is plenty that can be done here. Also intake pipe could be closing and is a common problem on there too

thanx for your help mate
I will fit the bov and fuel pump this weekend then I might bring it down for you to have a play with next weekend if it suits?
cheers

 

[sparra04]

I should mention it has a 3'' turbo back stainless xforce fitted
I will also unplug boost gauge and replug the std one in and see what it reads

 

[navaranewb]

thanx for your help mate
I will fit the bov and fuel pump this weekend then I might bring it down for you to have a play with next weekend if it suits?
cheers

I should mention it has a 3'' turbo back stainless xforce fitted
I will also unplug boost gauge and replug the std one in and see what it reads

No issues mate just let me know and we can check it out. As for the standard boost gauge it is electronic and has a sender on the firewall. Is that where the gauge is displaying from or is it directly coming from a vacuum source on the intake?

 

[sparra04]

Didnt get too look at car yesterday, was on my way down to shed when I tripped over a carton of beer
will have another attempt later